Reese loves being chased. But it's the thrill of the hunt that she likes, not being caught. So she's come up with a genius solution. As soon as she knows you're about to catch her, she turns around with her hands up like bear claws and "RRRAAAWWRRR!!!" And voilà! the hunted becomes the hunter.
Then she chases you long enough to put some distance between the two of you when she can start running away again.